Investigations of the physiological and biochemical bases of patterns of primate behavior with particular emphasis on aspects of emotional behavior, namely, on the affectional and sexual responses, and also on the agonistic or aggressive responses. Special emphasis is given to the underlying endocrine and neurological mechanisms involved. Central to this program is the accurate quantification of primate behavior both in a dyadic situation and in the social group. BIBLIOGRAPHIC REFERENCES: Peri-ovulatory synchronisation of behaviour in male and female rhesus monkeys. Michael, R.P. & Bonsall, R.W. Nature (Lond.), 265, 463-465, 1977. A 3-year study of an annual rhythm in plasma androgen levels in male rhesus monkeys (Mocaca mulatta) in a constant laboratory environment. Michael, R.P. & Bonsall, R.W. J. Reprod. Fert., 49, 129-131, 1977.